Sunday, August 17, 2014

More Science: Microbes, Pathogens & Parasites

Time for another science roundup... this time -- biology!

==  Toxins, Viruses and Parasites ==

By some estimates, your body houses ten times more bacteria than cells with your DNA.  But that is only the start of our humiliation! DNA surveys now suggest that humans have thousands of viral species in and on us. Most of them likely coexist within our gut in peace and harmony. This notion - of relatively harmless viruses that therefore have escaped notice by science - has been around a while. It features prominently in my short story “The Giving Plague.

AfterManyThe importance of the micro-biome - the vast array of symbiotic bacteria living in human bodies, especially the gut, was portrayed vividly in a 1930s novel by Aldous Huxley -- After Many a Summer Dies the Swan. But only now are we truly dialing into the importance of what Huxley then called “intestinal flora.” Now read how scientists are at last uncovering hints of huge communities of viruses that lurk below our notice, possibly affecting our health. These gut bacteria may even influence our food choices -- getting us to eat what they want. We have a lot to learn.

Seems that that engineered probiotic bacteria (“friendly” bacteria like those in yogurt) in the gut produce a therapeutic compound that inhibits weight gain, insulin resistance, and other adverse effects of a high-fat diet in mice. “Of course it’s hard to speculate from mouse to human.”   In fact, we are finding ever more longevity-related mouse results that have no bearing on humans! Still…

(BTW Huxley's novel is very good, if perhaps placid-paced by modern tastes. And it turns out on the last page to have been science fiction, all along!  In any event, it should be required reading for singularity-immortality guys and gals.)

Our Microbiome may be looking out for itself. Both Greg Bear and I have been talking about this for a long time… Greg in great detail in transfixing novels. Is your micro-biome affecting your behavior… for its own self-interest? We know that the paramecium Toxoplasma may be altering the personalities of perhaps half a billion people. 

In our guts, bacteria make some of the same chemicals that our neurons use to communicate with one another, such as dopamine and serotonin. And the microbes can deliver these neurological molecules to the dense web of nerve endings that line the gastrointestinal tract. 
A number of recent studies have shown that gut bacteria can use these signals to alter the biochemistry of the brain. Compared with ordinary mice, those raised free of germs behave differently in a number of ways. They are more anxious, for example, and have impaired memory.

Gut bacteria may also play a role in autism: research suggests that restoring microbial balance could alleviate some of the behavioral symptoms of autism.

Funny how we're on a roll about symbiosis between micro-organisms and macro-fauna today. It's all interconnected. As Greg Bear shows in Vitals, Kim Stanley Robinson showed in the Mars series, and I discussed in Earth (especially) and in Brightness Reef.

You can have  your personal microbiota tested at companies such as uBiome. 

== More biology! ==

Virus-Toxin-ParasiteSpeaking of strange interactions between the micro and macro... Toxoplasma gondii (T. gondii) is a single-celled parasite that has infested many modern human societies that keep cats, and as many as 60 million americans. Its subtle effects may include warping personality! (And sometimes physical illness.) Now some researchers claim that TG may be a good model for stimulating the immune system against cancer. Okay. But don’t go rushing to sniff your cat’s litter box. As I said, TG may be doing humanity vast harm by affecting our personalities, exacerbating our rising inability to negotiate and solve problems.  In any event, we see no correlation between TG sufferers and reduced cancer levels. Still, maybe there’s a usable connection. Let's hope this pans out. Go science.

Other researchers have found that a modified version of a toxic bacterium may help shrink cancerous tumors.

More on microbes, pathogens and parasites: Eight diseases to watch out for at the beach.

And while we're on the subject... Creepy slideshow: World's worst parasitic worms.

And in Wired: How Life made the leap from single-celled to multi-celled organisms.

Then there's... Shocking” news about electric eels and other voltage producing fish: "They're using the same genetic tools to build their electric organs in each lineage independently.”

==Planetary Ecosystems==

Tiny Flying Robots Are Being Built To Pollinate Crops Instead Of Real Bees. And sure, there’s a chilling aspect — which the Greenpeace site very cleverly conveys with this creepy satire, reminding us that cautionary criticism is the only way to expose possible errors….

Still, those who deride any and all forms of technological remediation as inherently bad, e.g. that it might reduce the imperative to save real bees, have got something wrong with their perception of human nature. It is possible to move forward in many directions, at once, toward the goal of saving the world -- as it was both consciousness raising and high technology that enabled us to save the whales. 

And yes, while top priority goes to reducing our impact-damage and preserving the natural ways. (I am taking part. Having provided bee swarms with makeshift shelters in the past, up on a nearby hill… I’ve now set up a real hive box… why not?) Still, our worst problem is single-minded monomaniac prescribers, who declare that there is only one, zero-sum, answer to anything. We need to move on all fronts, at once.

amphibians-extinctionYou will spend some time exploring this interesting — and disturbing — graphic: A Disappearing Planet, charting genuses and species bordering on extinction. Amphibians are in real trouble. Heck we all are. Though there's still hope.

Can we stop a killer fungus killing off amphibians?

Do offshore wind farms create fecund artificial reefs? Seals who cluster and forage seem to think so.

Remain agile.  Let's learn to be good planetary managers.


Jason said...

Hey David. Interesting stuff. You might like seeing this veterinarian's blog on "FIAF" - Fasting Imposed Adipose Factor, or how your gut biome controls how well your adipocytes can release fat...really interesting stuff. The guy goes into the actual signaling chemicals made by the gut and liver.


LarryHart said...

@Dr Brin,

Off-topic, but a question for you...

So my daughter buys a new sweatshirt in Washington DC with words across the front, one of which is "AUTHENTIC". Only I can only see the middle of the word. And I'm noticing that the center spells a word "HE", and that if you include the T before, it's still a word "THE" and likewise if you include the N afterward, you still have a word "THEN".

Wondering how long I can keep up this fun game, I was suddenly struck with the "word" "UTHEN", which is, of course, the name of one of your Quehen characters in the second Uplift trilogy.

And just because I'm fascinated by the way writers' minds work, I wondered if that was how you came up with that name in the first place.

Paul451 said...

US media reporting on Ferguson as if it were in another country:

And, oh apropos of nothing, Facebook is thinking about adding a [satire] tag to stories in feeds which come from fake news sites, due to misunderstandings by some users...

["when imlzard" I will bask, oh how I will bask.]

Paul Shen-Brown said...

Dear Dr. Brin,

On helping out the bees (the natural ones) Marla Spivak did a good TED Talk on why they are disappearing, and suggests we plant our yards with wildflowers that bloom at different times of year, to provide them with nectar year round. My daughter and I dug out most of our grass and planted a mix of native and drought-tolerant flowers. It has cut our water bill, in a drought-stricken region, and I certainly have the little buzzers flying around much more than before.

Tony Fisk said...

Considering what's been happening in the last hour, US media probably wish Ferguson *was* in another country.

Who's bright idea was it to invoke a curfew the day after the community leaders successfully managed to control out of town looters?

Seems it's Police business to maintain war and Mordor.

Acacia H. said...

Not sure if you're aware of this or not: there's a 20-minute Star Trek "documentary" called Prelude to Axanar concerning the Four Year War between the Federation and Klingon Empire... and a Kickstarter to produce the Battle of Axanar.

Rob H.

David Brin said...

LarryHart sorry! Great game though! An Uthenti = a super advanced Bantu tribe….?

Larry C. Lyons said...

An interesting chart. It looks like Ebola is following the paths of the major cross Africa highways.

Alfred Differ said...

What got my attention was recent work suggesting that removal of the parasites might be damaging too. I'm no fan of parasitic worms, but I dislike auto-immune disorders that seem to come out of nowhere too. I'm thankful that personal genetic testing costs are dropping quickly as that seems to be the only way to measure what is happening on this front. Person X removes parasite Y and disorder Z occurs with a probability P. Sigh.

Paul451 said...

The 500m limit on the LTE peer-to-peer seems pretty pathetic.

David Brin said...

My Ice Bucket ALS challenge video is up! It's all YOUR fault!!! (Those of you who ponied up for a good cause. Clearly I suffered terribly!

Alex Tolley said...

Our microbiome seems to be far more important than we ever thought. The gut populations influence our digestion and and we now know antibiotic use can have a serious impact on a range of health issues including obesity. Fecal transplants are being used to restore healthier biomes. There has been work showing that bacteria are involved in our responses to sex hormones during development. That we also have viruses tagging along should not be a surprise. They may well play a role in checking bacterial growth as well. Greg Bear's "Vitals" was a seriously scary read.

All this has implications for healthcare. We seem to be ending the antibiotic era, which was always a very blunt instrument. Using more targeted methods will be more expensive and difficult, but potentially more sustainable. Whether bacteria and viruses are the best approach for cancers, or our immune system is a better approach is still to be determined. But we do seem to finally be exiting the use of cytotoxic drugs in favor of better targeted approaches. The successes are building and one can hope that cancers will be treated far more humanely and effectively in the future.

Alex Tolley said...

Re: Tiny Flying Robots Are Being Built To Pollinate Crops

What could possible go wrong? :)
I could see there could be an interesting use of such pollinators as surveillance/sousveillance devices, but the potential for crop failure due to some unexpected higher order failure worries me. And what about hostage taking opportunities - food for thought? ($10m or the peach harvest fails!) Technology often drives out biologic competitors, so it could worsen the natural pollinator situation. How convenient if you want to grow certain crops that you need the mechanical pollinators too, because the natural ones cannot tolerate the high doses of insecticides or gene-engineered toxins.

Now on a space colony, they make make sense if the ecosystem needs to be kept simple.

Alex Tolley said...

@alfred - adding parasitic worms to cure certain ailments is quite possible. Definitely a yuck factor there. Maybe we need to rethink leeches too?

Paul Shen-Brown said...

Scientific American just put out a brief article on a possible relationship between intestinal microflora and autism, suggesting that probiotics may become a useful treatment. This idea has been explored before and seems to be coming back. I have personal experience that suggests the connection could be real.

I would agree with Alex that artificial pollinators would be a logical choice for an artificial ecosystem like a space colony. For here on Earth, I would prefer to stick with the bees. Ecosystems are too complex to successfully predict (except in very general terms) what will happen if we eradicate an entire species, or other such tinkerings.

Tony Fisk said...

Re: Bee-bot pollinators.

These may be useful in some circumstances where bees can't survive but, as other commenters have noted, they also have the potential to disenfranchise the natural ecosystem, with unforeseen consequences.

As a relevant aside, I recently caught up with 'The Windup Girl'; a pretty harrowing and nasty account of life in a future Asia riven by corporate eco-warfare. Monsanto & co. gone truly rogue.

Not a book I cared to finish; being more than a little over the top dystopic with *none* of the characters having many redeeming features. I think Heinlein would have understood why that would be.

Possibly the same concerns can be applied to gut biome modelling (eg: imagine a specially tailored yoghurt culture you *need* to maintain a healthy gut). For now, though, I'm fine with fecal transplants.

locumranch said...

The truth is that biological organisms evolved in a biologically competitive environment -- what is commonly known as 'filth' -- meaning that (1) filthiness is our normal (aka 'ideal') state of being and (2) the current culture of (godly) cleanliness is both irrational and actively harmful.

Of course, a modicum of cleanliness does have its place, especially in challenging medical environments, but that does not justify our current 'more is better' tendencies toward environmental and household sterility as this 'more is better' assumption is tantamount to cultural insanity, as is the contrawise insistence on the perfectibility of any other 'more is better' ideal biome composed of designer microbials.


Acacia H. said...

Here, Dr. Brin, an article about the largest Science Fiction library in the world and the threat new management is posing to it.

Rob H.

David Brin said...

Rob H. I am hip deep in the fight to save the Eaton Collection.

David Brin said...


Carlo Maley said...

Dear Dr. Brin,

I'm one of the authors on that "Is eating behavior manipulated by the gastrointestinal microbiota?" paper that you discussed above (it should soon be open access at Bioessays). I just wanted to thank you and give you the credit you deserve for thinking about these issues long before we did. I read and was very affected by the Giving Plague when I was in graduate school. In fact, my lab has an entirely different side project inspired by that story. I gave the story to Dr. Athena Aktipis who used it in her prosociality seminar at U. Penn. She was the one that came up with the idea that led to the paper you discussed (she is the senior author). So you have affected both of our thinking. I hope to meet you in person some day.

Carlo Maley